Refrigerant generator and circulator



g- 1932- R. v. GRAYSON 1,869,683

REFRIGERANT GENERATOR AND CIRCULATOR Filed May 6, 1931 summit Fatented Aug. 2, 1932 STATES 'r OFFICE RALPH. V. GRAYSON, OF ATLANTA, GEORGIA marina enunaa'roa CIRCULATOR Application filed m e, 1931. Serial at. 535,527.,

This invention relates to apparatus for generating a refrigerative fluid and then through pressure eventuating from the generation of the fluid, circulating the fluid in a chamber to be refrigerated.

The principal object of the invention is to provide a self contained and preferably portable unit for generating and circulating the refrigerating fluid, particularly adapted to m be associated with consignments of perishable products in freight cars, for refrigerating t e same.

A more specific object of the invention is to provide, for refri erating an enclosed space such as the interior of a freight car, a

unitcomprising a carbon dioxide ice -con tainer in combination with a turbine and an impeller, so related that the expansion of the dry ice creates a pressure, utilized in the turbine, which in turn actuates the impeller and circulates the cold carbon dioxide gas exhausting from the turbine, through the car space.

Another object of the invention is to pro-' vide an automatic control through which the pressure in the carbon dioxide container is kept constant, the revolution of the impeller being accelerated by the admission of more gas to the turbine when the rate of evaporation of the carbon dioxide ice increases as the car travels into a warmer climate, and vice versa, the rate of circulation varying directly with tlIEIfltG-Of evaporation.

Still another ob ect of the invention relates to a device of t e character described in which the turbine and/or control valve are mounted on the outside of a reversible head ters of reference have been employed throughout the several figures to deslgnate identical parts, Figure 1 is a longitudinal section through a freight car illustrating a refrigeration system of which the apparatus constituting the present invention forms a part.

the refrigerating unit.

Figure 3 is a front view.

Figure 4. is a vertical section through the control valve.

Referring now-in detail to the several fig ures and first adverting to Figure 1, the numeral 1 represents a freight car, having a false floor 2, and partitions 3 and 4 arranged in spaced relation to the end walls of the car. flhis is a conventional structure in refrigerated freight cars, the space between the end walls and partitions being utilized for salt and ice bunkers,while the space be neath the false floor receives by gravity the cooled air descending from said bunkers.

In the present invention the salt and ice is not used but the false floor and the end partitions define respectively with the bottom and end walls of the car and the space in the upper part of the car above the load line, a circuitous path for-the carbon dioxide gas which is the preferred cooling medium contemplated in the present invention although it is of course within the scope of the invention to substitute such other cooling media as may be found practical or preferred.

The refrigerating unit of the present invention comprises a container 6, preferably cylindrical as shown, having a removable head 7 secured in any suitable gas-tight manner as by the bolts 8 indicated in Figure 3. By removing the head 8 the container may be charged with blocks, 9 of carbon dioxide ice. After being thus charged the head is replaced. A turbine represented somewhat diagrammaticall at 10 in Figure 2 is secured to the outsi e of the head 7, said turbine being in communication with the chamber of the container 9 b way of a conduit 11. An impeller 12 1s suitably driven by the turbine.

Figure 2 is a longitudinal section through As'the carbon dioxide ice'evaporates by absorbing heat from the: interior of the freight car, cold carbon dioxide gas is generated building up -a pressure in the container 6 causing a flow of the'carbon dioxide gas through the conduit 11 and through the turbine, actuating the latter and revolving the impeller 12. Due to its doing work in the turbine, the carbon dioxide gas suffers a further temperature drop and issues from the exhaust of the'turbine as an extremely cold refrigerative fluid. This exhaust is caught by the -impeller 12 and circulated throu h the freight car in the manner indi cated y the arrows inFigure 1.

Due to diurnal temperature-changes and also the movement'iof the freight car from one latitude to another the temperature-of the interior of the freight car tends to vary and the rate of evaporation of the carbon dioxide ice fluctuates accordingly. When the temperature within the freight car rises, a superior pressure tends to build up within the" container 6 and the converse is true when the temperature of the car falls. It is Obvious the circulationof refrigerant through the freight car should be accelerated as the car temperature tends to increase and this is accomplished. by controlling the admission of the carbon d oxide gas to the turbine.

,The control means comprises a pressure responsive valve 12 in the conduit 11, the movements of which are governed by diaphragm 13. One side of said diaphragm 1S subjected in a chamber 14: to the pressure of the gas within thecontainer 6. A spring 15 bearlng against the opposite of the diaphragm balances the fluid normal pressure upon said diaphragm; The valve 12 is aifixed in any suitable manner to the diaphragm and is preferably guided in the conduit 11 by a stem 16. When the pressure in the container 6 rises the diaphragm is depressed against the tension of the spring 15,

increasing the opening of the valve 12 and admitting more fluid to the turbine. When the pressure inthe container 6 declines the diaphragm is returned in the direction of its normal position by the spring 15, and the valve 12 correspondingly closed, reducing the flowto the turbine.

-It is to be understood that the specific structure of the valve is immaterial to the invention and that any valve or other flow control means may be employed.

In itspreferred embodiment, it is contemplated that the refrigerating unit shall be portable so that it may if desired be furnished by the shipper of the consignment and placed upon the top of the shipment after the latter has been properly allocated in the freight car.. If desired however, the refrigerating unit may be part of the car equipment.

isoaeee In its preferred form, the detachable head 7 can be inverted so as to enclose the turbine 9 and the valve control mechanism within the chamber of the container. In shipping the unit back to the point of charging, the impeller may be removed and placed within the container and the head replaced in inverted position so as not only to protect the parts normally attached to the outer face but to conserve space.

In the normal refrigerated car in which the salt and ice bunkers aredepended upon forthe cooling function, the space in the top of the car above the shipment is usually 1nefliciently cooled since the absence of positive circulating means limits the refrigerating action to a mere convection descent of cold air, which settles in the bottom portion of the car. By the present invention a positive circulation is set up and maintained throughout the entire space surrounding the products to be refrigerated, and the refrigcrating-efficiency is enhanced by the acute coldness of the carbon dioxide gas which suffers not only the normal temperature drop due'to it's change of state from a solid to an expanding gas, but a further temperature drop in doing work in the turbine.

While I have in the above disclosure disclosed a preferred and practical form of my invention, it is to be understood that the details of construction as shown are merel b way of example and not to be considered imitative in their bearing upon the scope of the invention as claimed.

What I claim as my invention is:

1. Refrigerant generator and circulator comprising a tank for generating a cold gaseous refrigerant under pressure, a fluid pressure motor actuated by said refri erant, in which, in doing work, it suffers a urther temperature drop, and an impeller operated ,by said fluid pressure motor for circulating the cold refrigerant exhausting from said motor.

2. Refrigerating system comprising walls .forming a refrigerated chamber, means in said chamber for forming a circuitous circulation path, and a refrigerant generator and circulator positioned at the upper portion of said circulation path comprising means for generating a cold fluid under pressure, and

means actuated by the pressure of said fluid for circulating said fluid.

3. Refrigerating system comprising walls forming a refrigerated chamber, means in said chamber forming a circuitous circulation fluid pressure motor for circulating the cold refrigerant exhausting from said motor.

4. Refrigerant generator and circulator comprising a receptacle for generating a cold gaseous refrigerant from a refrigerant in solidified form, a fluid pressure motor actuated by said refrigerant a conduit connecting said receptacle with said motor, an impeller driven by said motor for circulating the cold gaseous refrigerant exhausting from said motor, and a pressure regulator in said conduit for maintaining a substantially constant pressure in said receptacle.

5. A refrigerant generator and circulator comprising a receptacle for generating a cold fluid refrigerant under pressure from the refri erant in solidified form, a detachable hea for said rece tacle a turbine secured to the outer face 0? said head and communicating with said receptacle, said turbine being driven by the refrigerant under pressure from said receptacle, said turbine being so positioned on said head as to ermit inversion of said head with said turbine within said receptacle.

In testimony whereof I aflix my si ature.

RALPH V. GRA SON. 

